Conventionally, a method has been known where an authentication server receives a request for network access authentication from an authentication client and performs a network access authenticating process. The conventional method has a problem in that a network access authenticating process cannot be performed in conformity with the connection configuration of the authentication client. That is, determination cannot be performed of whether to allow or reject connection in consideration of which authentication relay or network the authentication client is connected to.
For instance, it is assumed that the authentication client is a HEMS (home energy management system), and the authentication relay is a smart meter. In this case, a HEMS at a certain home may wish to allow connection to a smart meter at the same home but to prevent from being connected to a smart meter at another home. In the case of wireless communication, it is a matter of course to assume that an operation where a HEMS at a certain home intends to connect to a smart meter at another home occurs. Passwords specific to respective homes may be set in HEMSs and smart meters, and authentication processes may be performed using the passwords. Unfortunately, it is complicated for a user to set a password. On the contrary, in some cases, it may be desired that free connection to any party be allowed between smart meters, to achieve a flexible network.